// This file is distributed under the BSD License.
// See "license.txt" for details.
// Copyright 2009-2012, Jonathan Turner (jonathan@emptycrate.com)
// Copyright 2009-2018, Jason Turner (jason@emptycrate.com)
// http://www.chaiscript.com

// This is an open source non-commercial project. Dear PVS-Studio, please check it.
// PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com

/// \file
/// This file contains utility functions for registration of STL container
/// classes. The methodology used is based on the SGI STL concepts.
/// http://www.sgi.com/tech/stl/table_of_contents.html

#ifndef CHAISCRIPT_BOOTSTRAP_STL_HPP_
#define CHAISCRIPT_BOOTSTRAP_STL_HPP_

#include <functional>
#include <memory>
#include <stdexcept>
#include <typeinfo>
#include <vector>

#include "bootstrap.hpp"
#include "boxed_value.hpp"
#include "dispatchkit.hpp"
#include "operators.hpp"
#include "proxy_constructors.hpp"
#include "register_function.hpp"
#include "type_info.hpp"

namespace chaiscript::bootstrap::standard_library {
  /// Bidir_Range, based on the D concept of ranges.
  /// \todo Update the Range code to base its capabilities on
  ///       the user_typetraits of the iterator passed in
  template<typename Container, typename IterType>
  struct Bidir_Range {
    using container_type = Container;

    constexpr Bidir_Range(Container &c)
        : m_begin(c.begin())
        , m_end(c.end()) {
    }

    constexpr bool empty() const noexcept { return m_begin == m_end; }

    constexpr void pop_front() {
      if (empty()) {
        throw std::range_error("Range empty");
      }
      ++m_begin;
    }

    constexpr void pop_back() {
      if (empty()) {
        throw std::range_error("Range empty");
      }
      --m_end;
    }

    constexpr decltype(auto) front() const {
      if (empty()) {
        throw std::range_error("Range empty");
      }
      return (*m_begin);
    }

    constexpr decltype(auto) back() const {
      if (empty()) {
        throw std::range_error("Range empty");
      }
      auto pos = m_end;
      --pos;
      return (*(pos));
    }

    IterType m_begin;
    IterType m_end;
  };

  namespace detail {
    template<typename T>
    size_t count(const T &t_target, const typename T::key_type &t_key) {
      return t_target.count(t_key);
    }

    template<typename T>
    void insert(T &t_target, const T &t_other) {
      t_target.insert(t_other.begin(), t_other.end());
    }

    template<typename T>
    void insert_ref(T &t_target, const typename T::value_type &t_val) {
      t_target.insert(t_val);
    }

    /// Add Bidir_Range support for the given ContainerType
    template<typename Bidir_Type>
    void input_range_type_impl(const std::string &type, Module &m) {
      m.add(user_type<Bidir_Type>(), type + "_Range");

      copy_constructor<Bidir_Type>(type + "_Range", m);

      m.add(constructor<Bidir_Type(typename Bidir_Type::container_type &)>(), "range_internal");

      m.add(fun(&Bidir_Type::empty), "empty");
      m.add(fun(&Bidir_Type::pop_front), "pop_front");
      m.add(fun(&Bidir_Type::front), "front");
      m.add(fun(&Bidir_Type::pop_back), "pop_back");
      m.add(fun(&Bidir_Type::back), "back");
    }

    /// Algorithm for inserting at a specific position into a container
    template<typename Type>
    void insert_at(Type &container, int pos, const typename Type::value_type &v) {
      auto itr = container.begin();
      auto end = container.end();

      if (pos < 0 || std::distance(itr, end) < pos) {
        throw std::range_error("Cannot insert past end of range");
      }

      std::advance(itr, pos);
      container.insert(itr, v);
    }

    /// Algorithm for erasing a specific position from a container
    template<typename Type>
    void erase_at(Type &container, int pos) {
      auto itr = container.begin();
      auto end = container.end();

      if (pos < 0 || std::distance(itr, end) < (pos - 1)) {
        throw std::range_error("Cannot erase past end of range");
      }

      std::advance(itr, pos);
      container.erase(itr);
    }
  } // namespace detail

  template<typename ContainerType>
  void input_range_type(const std::string &type, Module &m) {
    detail::input_range_type_impl<Bidir_Range<ContainerType, typename ContainerType::iterator>>(type, m);
    detail::input_range_type_impl<Bidir_Range<const ContainerType, typename ContainerType::const_iterator>>("Const_" + type, m);
  }

  /// Add random_access_container concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/RandomAccessContainer.html
  template<typename ContainerType>
  void random_access_container_type(const std::string & /*type*/, Module &m) {
    // In the interest of runtime safety for the m, we prefer the at() method for [] access,
    // to throw an exception in an out of bounds condition.
    m.add(fun([](ContainerType &c, int index) -> typename ContainerType::reference {
            /// \todo we are preferring to keep the key as 'int' to avoid runtime conversions
            /// during dispatch. reevaluate
            return c.at(static_cast<typename ContainerType::size_type>(index));
          }),
          "[]");

    m.add(fun([](const ContainerType &c, int index) -> typename ContainerType::const_reference {
            /// \todo we are preferring to keep the key as 'int' to avoid runtime conversions
            /// during dispatch. reevaluate
            return c.at(static_cast<typename ContainerType::size_type>(index));
          }),
          "[]");
  }

  /// Add assignable concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/Assignable.html
  template<typename ContainerType>
  void assignable_type(const std::string &type, Module &m) {
    copy_constructor<ContainerType>(type, m);
    operators::assign<ContainerType>(m);
  }

  /// Add container resize concept to the given ContainerType
  /// http://www.cplusplus.com/reference/stl/
  template<typename ContainerType>
  void resizable_type(const std::string & /*type*/, Module &m) {
    m.add(fun([](ContainerType *a, typename ContainerType::size_type n, const typename ContainerType::value_type &val) {
            return a->resize(n, val);
          }),
          "resize");
    m.add(fun([](ContainerType *a, typename ContainerType::size_type n) { return a->resize(n); }), "resize");
  }

  /// Add container reserve concept to the given ContainerType
  /// http://www.cplusplus.com/reference/stl/
  template<typename ContainerType>
  void reservable_type(const std::string & /*type*/, Module &m) {
    m.add(fun([](ContainerType *a, typename ContainerType::size_type n) { return a->reserve(n); }), "reserve");
    m.add(fun([](const ContainerType *a) { return a->capacity(); }), "capacity");
  }

  /// Add container concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/Container.html
  template<typename ContainerType>
  void container_type(const std::string & /*type*/, Module &m) {
    m.add(fun([](const ContainerType *a) { return a->size(); }), "size");
    m.add(fun([](const ContainerType *a) { return a->empty(); }), "empty");
    m.add(fun([](ContainerType *a) { a->clear(); }), "clear");
  }

  /// Add default constructable concept to the given Type
  /// http://www.sgi.com/tech/stl/DefaultConstructible.html
  template<typename Type>
  void default_constructible_type(const std::string &type, Module &m) {
    m.add(constructor<Type()>(), type);
  }

  /// Add sequence concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/Sequence.html
  template<typename ContainerType>
  void sequence_type(const std::string & /*type*/, Module &m) {
    m.add(fun(&detail::insert_at<ContainerType>), []() -> std::string {
      if (typeid(typename ContainerType::value_type) == typeid(Boxed_Value)) {
        return "insert_ref_at";
      } else {
        return "insert_at";
      }
    }());

    m.add(fun(&detail::erase_at<ContainerType>), "erase_at");
  }

  /// Add back insertion sequence concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/BackInsertionSequence.html
  template<typename ContainerType>
  void back_insertion_sequence_type(const std::string &type, Module &m) {
    m.add(fun([](ContainerType &container) -> decltype(auto) {
            if (container.empty()) {
              throw std::range_error("Container empty");
            } else {
              return (container.back());
            }
          }),
          "back");
    m.add(fun([](const ContainerType &container) -> decltype(auto) {
            if (container.empty()) {
              throw std::range_error("Container empty");
            } else {
              return (container.back());
            }
          }),
          "back");

    using push_back = void (ContainerType::*)(const typename ContainerType::value_type &);
    m.add(fun(static_cast<push_back>(&ContainerType::push_back)), [&]() -> std::string {
      if (typeid(typename ContainerType::value_type) == typeid(Boxed_Value)) {
        m.eval("# Pushes the second value onto the container while making a clone of the value\n"
               "def push_back("
               + type
               + " container, x)\n"
                 "{ \n"
                 "  if (x.is_var_return_value()) {\n"
                 "    x.reset_var_return_value() \n"
                 "    container.push_back_ref(x) \n"
                 "  } else { \n"
                 "    container.push_back_ref(clone(x)); \n"
                 "  }\n"
                 "} \n");

        return "push_back_ref";
      } else {
        return "push_back";
      }
    }());

    m.add(fun(&ContainerType::pop_back), "pop_back");
  }

  /// Front insertion sequence
  /// http://www.sgi.com/tech/stl/FrontInsertionSequence.html
  template<typename ContainerType>
  void front_insertion_sequence_type(const std::string &type, Module &m) {
    using push_ptr = void (ContainerType::*)(typename ContainerType::const_reference);
    using pop_ptr = void (ContainerType::*)();

    m.add(fun([](ContainerType &container) -> decltype(auto) {
            if (container.empty()) {
              throw std::range_error("Container empty");
            } else {
              return (container.front());
            }
          }),
          "front");

    m.add(fun([](const ContainerType &container) -> decltype(auto) {
            if (container.empty()) {
              throw std::range_error("Container empty");
            } else {
              return (container.front());
            }
          }),
          "front");

    m.add(fun(static_cast<push_ptr>(&ContainerType::push_front)), [&]() -> std::string {
      if (typeid(typename ContainerType::value_type) == typeid(Boxed_Value)) {
        m.eval("# Pushes the second value onto the front of container while making a clone of the value\n"
               "def push_front("
               + type
               + " container, x)\n"
                 "{ \n"
                 "  if (x.is_var_return_value()) {\n"
                 "    x.reset_var_return_value() \n"
                 "    container.push_front_ref(x) \n"
                 "  } else { \n"
                 "    container.push_front_ref(clone(x)); \n"
                 "  }\n"
                 "} \n");
        return "push_front_ref";
      } else {
        return "push_front";
      }
    }());

    m.add(fun(static_cast<pop_ptr>(&ContainerType::pop_front)), "pop_front");
  }

  /// bootstrap a given PairType
  /// http://www.sgi.com/tech/stl/pair.html
  template<typename PairType>
  void pair_type(const std::string &type, Module &m) {
    m.add(user_type<PairType>(), type);

    m.add(fun(&PairType::first), "first");
    m.add(fun(&PairType::second), "second");

    basic_constructors<PairType>(type, m);
    m.add(constructor<PairType(const typename PairType::first_type &, const typename PairType::second_type &)>(), type);
  }

  /// Add pair associative container concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/PairAssociativeContainer.html

  template<typename ContainerType>
  void pair_associative_container_type(const std::string &type, Module &m) {
    pair_type<typename ContainerType::value_type>(type + "_Pair", m);
  }

  /// Add unique associative container concept to the given ContainerType
  /// http://www.sgi.com/tech/stl/UniqueAssociativeContainer.html
  template<typename ContainerType>
  void unique_associative_container_type(const std::string & /*type*/, Module &m) {
    m.add(fun(detail::count<ContainerType>), "count");

    using erase_ptr = size_t (ContainerType::*)(const typename ContainerType::key_type &);

    m.add(fun(static_cast<erase_ptr>(&ContainerType::erase)), "erase");

    m.add(fun(&detail::insert<ContainerType>), "insert");

    m.add(fun(&detail::insert_ref<ContainerType>), []() -> std::string {
      if (typeid(typename ContainerType::mapped_type) == typeid(Boxed_Value)) {
        return "insert_ref";
      } else {
        return "insert";
      }
    }());
  }

  /// Add a MapType container
  /// http://www.sgi.com/tech/stl/Map.html
  template<typename MapType>
  void map_type(const std::string &type, Module &m) {
    m.add(user_type<MapType>(), type);

    using elem_access = typename MapType::mapped_type &(MapType::*)(const typename MapType::key_type &);
    using const_elem_access = const typename MapType::mapped_type &(MapType::*)(const typename MapType::key_type &) const;

    m.add(fun(static_cast<elem_access>(&MapType::operator[])), "[]");

    m.add(fun(static_cast<elem_access>(&MapType::at)), "at");
    m.add(fun(static_cast<const_elem_access>(&MapType::at)), "at");

    if (typeid(MapType) == typeid(std::map<std::string, Boxed_Value>)) {
      m.eval(R"(
                    def Map::`==`(Map rhs) {
                       if ( rhs.size() != this.size() ) {
                         return false;
                       } else {
                         auto r1 = range(this);
                         auto r2 = range(rhs);
                         while (!r1.empty())
                         {
                           if (!eq(r1.front().first, r2.front().first) || !eq(r1.front().second, r2.front().second))
                           {
                             return false;
                           }
                           r1.pop_front();
                           r2.pop_front();
                         }
                         true;
                       }
                   } )");
    }

    container_type<MapType>(type, m);
    default_constructible_type<MapType>(type, m);
    assignable_type<MapType>(type, m);
    unique_associative_container_type<MapType>(type, m);
    pair_associative_container_type<MapType>(type, m);
    input_range_type<MapType>(type, m);
  }

  /// http://www.sgi.com/tech/stl/List.html
  template<typename ListType>
  void list_type(const std::string &type, Module &m) {
    m.add(user_type<ListType>(), type);

    front_insertion_sequence_type<ListType>(type, m);
    back_insertion_sequence_type<ListType>(type, m);
    sequence_type<ListType>(type, m);
    resizable_type<ListType>(type, m);
    container_type<ListType>(type, m);
    default_constructible_type<ListType>(type, m);
    assignable_type<ListType>(type, m);
    input_range_type<ListType>(type, m);
  }

  /// Create a vector type with associated concepts
  /// http://www.sgi.com/tech/stl/Vector.html
  template<typename VectorType>
  void vector_type(const std::string &type, Module &m) {
    m.add(user_type<VectorType>(), type);

    m.add(fun([](VectorType &container) -> decltype(auto) {
            if (container.empty()) {
              throw std::range_error("Container empty");
            } else {
              return (container.front());
            }
          }),
          "front");

    m.add(fun([](const VectorType &container) -> decltype(auto) {
            if (container.empty()) {
              throw std::range_error("Container empty");
            } else {
              return (container.front());
            }
          }),
          "front");

    back_insertion_sequence_type<VectorType>(type, m);
    sequence_type<VectorType>(type, m);
    random_access_container_type<VectorType>(type, m);
    resizable_type<VectorType>(type, m);
    reservable_type<VectorType>(type, m);
    container_type<VectorType>(type, m);
    default_constructible_type<VectorType>(type, m);
    assignable_type<VectorType>(type, m);
    input_range_type<VectorType>(type, m);

    if (typeid(VectorType) == typeid(std::vector<Boxed_Value>)) {
      m.eval(R"(
                    def Vector::`==`(Vector rhs) {
                       if ( rhs.size() != this.size() ) {
                         return false;
                       } else {
                         auto r1 = range(this);
                         auto r2 = range(rhs);
                         while (!r1.empty())
                         {
                           if (!eq(r1.front(), r2.front()))
                           {
                             return false;
                           }
                           r1.pop_front();
                           r2.pop_front();
                         }
                         true;
                       }
                   } )");
    }
  }

  /// Add a String container
  /// http://www.sgi.com/tech/stl/basic_string.html
  template<typename String>
  void string_type(const std::string &type, Module &m) {
    m.add(user_type<String>(), type);
    operators::addition<String>(m);
    operators::assign_sum<String>(m);
    opers_comparison<String>(m);
    random_access_container_type<String>(type, m);
    sequence_type<String>(type, m);
    default_constructible_type<String>(type, m);
    // container_type<String>(type, m);
    assignable_type<String>(type, m);
    input_range_type<String>(type, m);

    // Special case: add push_back to string (which doesn't support other back_insertion operations
    m.add(fun(&String::push_back), []() -> std::string {
      if (typeid(typename String::value_type) == typeid(Boxed_Value)) {
        return "push_back_ref";
      } else {
        return "push_back";
      }
    }());

    m.add(fun([](const String *s, const String &f, size_t pos) { return s->find(f, pos); }), "find");
    m.add(fun([](const String *s, const String &f, size_t pos) { return s->rfind(f, pos); }), "rfind");
    m.add(fun([](const String *s, const String &f, size_t pos) { return s->find_first_of(f, pos); }), "find_first_of");
    m.add(fun([](const String *s, const String &f, size_t pos) { return s->find_last_of(f, pos); }), "find_last_of");
    m.add(fun([](const String *s, const String &f, size_t pos) { return s->find_last_not_of(f, pos); }), "find_last_not_of");
    m.add(fun([](const String *s, const String &f, size_t pos) { return s->find_first_not_of(f, pos); }), "find_first_not_of");

    m.add(fun([](String *s, typename String::value_type c) -> decltype(auto) { return (*s += c); }), "+=");

    m.add(fun([](String *s) { s->clear(); }), "clear");
    m.add(fun([](const String *s) { return s->empty(); }), "empty");
    m.add(fun([](const String *s) { return s->size(); }), "size");

    m.add(fun([](const String *s) { return s->c_str(); }), "c_str");
    m.add(fun([](const String *s) { return s->data(); }), "data");
    m.add(fun([](const String *s, size_t pos, size_t len) { return s->substr(pos, len); }), "substr");
  }

  /// Add a MapType container
  /// http://www.sgi.com/tech/stl/Map.html
  template<typename FutureType>
  void future_type(const std::string &type, Module &m) {
    m.add(user_type<FutureType>(), type);

    m.add(fun([](const FutureType &t) { return t.valid(); }), "valid");
    m.add(fun([](FutureType &t) { return t.get(); }), "get");
    m.add(fun(&FutureType::wait), "wait");
  }
} // namespace chaiscript::bootstrap::standard_library

#endif
